Thinly interlaminated dolostones in the Middle Cambrian of Nevada and Utah are composed of evenly grained cryptocrystalline rhombs formed by primary and early diagenetic precipitation. Laminations may be the result of seasonal changes at site of deposition. Intraformation conglomerate in a matrix of fine-grained calcite indicates primary and early diagenetic origin for the dolomite. These coarse clastic rocks are the result of subaqueous processes. It is suggested that deposition was in area similar to Bahama Banks.